JCreasy
Member
I don't claim to be an expert on cg animation, but just based on what I've learned by following video games, I had alway assumed Pixar used raytracing to light their movies.
Turns out that's not true.
All their earlier films used hacks to get the results we've seen. Monster's University will be the first Pixar film to throughly implement ray tracing for their lighting.
Check out this interview with Chris Horne at Mason Smith's blog:
I was really impressed with how MU looked in the trailers and now I know why.
More at the link.
http://thisanimatedlife.blogspot.ch/2013/05/pixars-chris-horne-sheds-new-light-on.html
Turns out that's not true.
All their earlier films used hacks to get the results we've seen. Monster's University will be the first Pixar film to throughly implement ray tracing for their lighting.
Check out this interview with Chris Horne at Mason Smith's blog:
I was on MU from May 2012 until April 2013 -- so yeah I worked on it for a *very very* long time as far as the lighting department is concerned. When I joined it was only leads + 1 shot lighter and me. It was a blast to work on because we completely rewrote our lighting system to be a raytraced/GI system -- and since I was on early I got to test the boundaries of it and figure out how we should light the show from a technical aspect. We really explored the lighting system - and I feel like a significant amount of work we did back then is going to live on in the way we light shows with this new technology.
There's a huge difference in MU compared to past films. Even people that don't know anything about our tech change going in walk out going "HOLY CRAP!"....but they have a hard time putting their finger on why it looks so awesome. Personally I see a huge difference between MU and Brave - there's more shaping, more little splashes of color, and everything feels a little bit more dynamic and pulled together.
Historically we don't use raytracing. It wasn't until Cars that we actually supported raytracing (and even then it was a haphazard and mostly broken support). We really only used it for highly reflective smooth curved surfaces that absolutely needed to be truly reflected and not faked. We fake almost everything - mirrors, wet surfaces, eyes, shiny props like belt buckles/spoons/swords/etc. We obviously can't get away with that on Lightning McQueen - so we would cache out the scene into a brickmap (essentially a kd-tree with shading attached to the voxels) and fire rays against that (so even then....we aren't doing traditional raytracing).
So our Director of Photography went to a studio that is so clearly raytracing averse and essentially said "We're raytracing everything. True reflection and refraction in the eyes reflecting actual SCENE GEOMETRY and not a brickmap. Yep - we're refracting through the cornea onto the sclera and iris. Oh and all your shadows are raytraced now - no more shadowmaps.
I was really impressed with how MU looked in the trailers and now I know why.
More at the link.
http://thisanimatedlife.blogspot.ch/2013/05/pixars-chris-horne-sheds-new-light-on.html